# math

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the number of red marbles varies inversely as the square of the number of blue marbles. when there were four reds, there were 20 blues. How many reds would there be if there were only four blues?

• math -

100

• math -

r = k/b^2 , r is red, b is blue

4 = k/400
k = 1600
then r = 1600/b^2

when b = 4
r = 1600/16
= 100

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